1. Field of the Invention
This invention relates to an apparatus for recording a video signal on a magnetic tape.
2. Description of the Related Art
Some video tape recorders (VTR""s) are based on a standard format referred to as a VHS format. There is an S-VHS format which improves over the VHS format. A VTR of the S-VHS standard can record and reproduce a video signal which is wider in frequency band and higher in picture quality than a video signal handled by a VTR of the VHS standard.
The VTR of the S-VHS standard uses an exclusive magnetic tape referred to as an S-VHS tape. The S-VHS tape is designed to more suit with a video signal having a wide frequency band and short wavelengths in comparison with a VHS tape.
In the VTR of the VHS standard, a video signal to be recorded is separated into luminance and chrominance signals. The luminance signal is converted or modulated into an FM (modulated) luminance signal having a frequency deviation of 3.4 to 4.4 MHz. The chrominance signals are down-converted into a low frequency band around 629 kHz. The FM luminance signal and the frequency-down-converted chrominance signals are combined before being recorded on a VHS tape.
In the VTR of the S-VHS standard, a video signal to be recorded is separated into luminance and chrominance signals. The luminance signal is converted or modulated into an FM (modulated) luminance signal having a frequency deviation of 5.4 to 7.0 MHz. The chrominance signals are down-converted into a low frequency band around 629 kHz. The FM luminance signal and the frequency-down-converted chrominance signals are combined before being recorded on an S-VHS tape.
The VTR of the VHS standard can use an S-VHS tape instead of a VHS tape. In general, the VTR of the S-VHS standard can operate in each of two different modes, a VHS mode and an S-VHS mode. During the VHS mode of operation of the S-VHS VTR, a video signal of the VHS format is recorded on a VHS tape or an S-VHS tape. During the S-VHS mode of operation of the S-VHS VTR, a video signal of the S-VHS format is recorded on an S-VHS tape.
In general, an S-VHS tape is contained in a cassette having an identification hole which indicates that the tape therein is of the S-VHS type. The VTR of the S-VHS standard has a function of sensing an identification hole in a tape cassette placed therein. When the S-VHS VTR senses an identification hole in a tape cassette, the S-VHS mode of operation is automatically started. On the other hand, when the S-VHS VTR fails to sense an identification hole in a tape cassette, the VHS mode of operation is started.
An advanced VTR detects characteristics of a used magnetic tape, and records a video signal on the magnetic tape under recording conditions (that is, the VHS mode or the S-VHS mode) determined in response to the detected tape characteristics. The advanced VTR can optimize signal recording tape by tape. Specifically, the advanced VTR implements a preliminary process before the recording of a video signal. During the preliminary process, the advanced VTR records and reproduces a test signal on and from a used magnetic tape. The advanced VTR detects characteristics of the magnetic tape (that is, the VHS standard tape or the S-VHS tape) from the reproduced test signal. Then, the advanced VTR records a video signal on the magnetic tape under recording conditions determined in response to the detected tape (the VHS standard tape or the S-VHS tape) characteristics.
As previously explained, the S-VHS VTR operates in the VHS mode when a VHS tape is used. Some VHS tapes have improved characteristics sufficient to store wide-band and high-quality video signals. In general, S-VHS tapes are higher in price than VHS tapes.
It is an object of this invention to provide a magnetic recording apparatus which can record a wide-band and high-quality video signal on an inexpensive magnetic tape such as a VHS tape.
A first aspect of this invention provides a magnetic recording apparatus comprising first means for processing an input video signal into a processing-resultant video signal having a first given frequency band; and second means for recording the processing-resultant video signal, which is generated by the first means, on a standard magnetic tape which is designed to record a standard-format video signal having a second given frequency band narrower than the first given frequency band.
A second aspect of this invention provides a magnetic recording apparatus comprising first means for processing an input video signal into one among a first standard-format video signal having a first given frequency band, a second standard-format video signal having a second given frequency band wider than the first given frequency band, and a processing-resultant video signal having a third given frequency band wider than the first given frequency band; second means for recording the first standard-format video signal, which is generated by the first means, on a first standard magnetic tape which is designed to record a first standard-format video signal; third means for recording the second standard-format video signal, which is generated by the first means, on a second standard magnetic tape which is designed to record a second standard-format video signal; and fourth means for recording the processing-resultant video signal, which is generated by the first means, on the first standard magnetic tape.
A third aspect of this invention is based on the second aspect thereof, and provides a magnetic recording apparatus further comprising fifth means for, in response to user""s request, deciding which of the first, second, and third standard-format video signals the first means processes the input video signal into; and sixth means for recording the video signal, which is decided by the fifth means, on a magnetic tape.
A fourth aspect of this invention is based on the second aspect thereof, and provides a magnetic recording apparatus wherein the processing-resultant video signal can be reproduced from the first standard magnetic tape by a magnetic reproducing apparatus for a second standard-format video signal and a second standard magnetic tape.
A fifth aspect of this invention is based on the second aspect thereof, and provides a magnetic recording apparatus further comprising fifth means for detecting whether or not the first standard magnetic tape is suited to recording of the process-resultant video signal.
A sixth aspect of this invention is based on the fifth aspect thereof, and provides a magnetic recording apparatus wherein the fifth means comprises sixth means for recording a test signal to the first standard magnetic tape; seventh means for reproducing the test signal from the first standard magnetic tape; and eighth means for detecting whether or not the first standard magnetic tape is suited to recording of the process-resultant video signal in response to a level of the reproduced test signal.
A seventh aspect of this invention is based on the sixth aspect thereof, and provides a magnetic recording apparatus wherein a recording level of the test signal is equal to a recording level of the process-resultant video signal.
An eighth aspect of this invention is based on the seventh aspect thereof, and provides a magnetic recording apparatus wherein the sixth means records the test signal at only a single recording level.
A ninth aspect of this invention is based on the seventh aspect thereof, and provides a magnetic recording apparatus wherein the sixth means records the test signal at a plurality of different recording levels, and the fourth means records the processing-resultant video signal at a recording level equal to a recording level among the plurality of the different recording levels at which a reproduction level is maximized.
A tenth aspect of this invention is based on the sixth aspect thereof, and provides a magnetic recording apparatus wherein the first means comprises a detail enhancer, a pre-emphasis circuit, a white/dark clip circuit, and a recording current equalizer, and further comprising ninth means for varying operation characteristics of at least one among the detail enhancer, the pre-emphasis circuit, the white/dark clip circuit, and the recording current equalizer in response to the level of the reproduced test signal.
An eleventh aspect of this invention provides a magnetic recording apparatus comprising first means for recording one of a first video signal of a normal-quality standard format and a second video signal of a high-quality standard format on one of a normal-quality standard tape and a high-quality standard tape; and second means for recording a third video signal on one of the normal-quality standard tape and the high-quality standard tape, the third video signal being closer in quality to the second video signal.
A twelfth aspect of this invention is based on the eleventh aspect thereof, and provides a magnetic recording apparatus further comprising third means for recording a test signal on one of the normal-quality standard tape and the high-quality standard tape; fourth means for reproducing the test signal from one of the normal-quality standard tape and the high-quality standard tape; and fifth means for selecting one of the first means and the second means in response to a level of the reproduced test signal, and for activating selected one of the first means and the second means.
A thirteenth aspect of this invention is based on the eleventh aspect thereof, and provides a magnetic recording apparatus further comprising third means for detecting whether or not a cassette containing one of the normal-quality standard tape and the high-quality standard tape has an identification hole; and fourth means for selecting one of the first means and the second means in response to a result of the detection by the third means, and for activating selected one of the first means and the second means.
A fourteenth aspect of this invention is based on the eleventh aspect thereof, and provides a magnetic recording apparatus further comprising third means for selecting one of the first means and the second means in response to user""s request, and for activating selected one of the first means and the second means.
A fifteenth aspect of this invention provides an apparatus for recording video information on a VHS standard tape which comprises first means for detecting whether or not a quality of the VHS standard tape exceeds a reference quality; second means for processing an input video signal into a first processing-resultant video signal with a first given frequency band when the first means detects that the quality of the VHS standard tape exceeds the reference quality; third means for processing the input video signal into a second processing-resultant video signal with a second given frequency band when the first means detects that the quality of the VHS standard tape does not exceed the reference quality, the second given frequency band being narrower than the first given frequency band; and fourth means for recording either the first processing-resultant video signal or the second processing-resultant video signal on the VHS standard tape.
A sixteenth aspect of this invention is based on the fifteenth aspect thereof, and provides an apparatus wherein the first means comprises means for recording a predetermined test signal on the VHS standard tape; means for reproducing the test signal from the VHS standard tape; and means for detecting whether or not the quality of the VHS standard tape exceeds the reference quality in response to a level of the reproduced test signal.